Yes, the word trinity does not appear in the Bible. No, it doesn’t matter. Theologians create concepts and words to explain what cannot be seen. For example, angels are spirit beings that we cannot see; demons are spirit beings we cannot see. So how do we know the difference?
We know them by what they do – the results of their being here on planet earth.
The same thing is true of the Trinity. We define God the Father, Jesus the Son and Holy Spirit not by what they are but by how we apprehend their impact on our life. The word “apprehend” is so full of meaning, and we simply do not use it enough. It means to reach out and take hold of an idea. (Sometimes an idea takes hold of us.)
People ask, How do you know you are saved? The average person says, I don’t know, I just do. This is not a very good explanation for others but the people who say this apprehend what salvation is to them. Bottom line for Christianity is that it is an act of faith based on the personal apprehension by the individual of the intervention of God ….. and a whole lot more as we grow..
So we apprehend Jesus as the Light of the World, (John 9:5) God as Light (1 John 1:5) and Holy Spirit as our personal light within. (John 15:26)
God is Father, (1 Corinthians 8:6) Jesus is His Son and a good friend to us, (John 20:31) and Holy Spirit then is the intimate knowledge that God is with us at all times. (John 16: 8 And when he is come, he will reprove the world of sin, and of righteousness, and of judgment.) We can expect new revelation about the future from him says this passage. Jesus didn’t save us, ascend to heaven and leave us with no tools!
God is the Judge (Psalm 50:6) sitting on the throne, Jesus is our lawyer, (1 John 2:1) and the Holy Spirit our probation officer. He’ll warn us when we are out of line. (John 16:13)
God created us, Jesus shed His blood for us, and the Holy Spirit advises us until we leave earth.
Again, to repeat, God as Trinity is not defined from what they are but how we understand them. If God can hold the whole world in His hands, explanations outside our own meager understanding beggar description. There is simply no reason to try. But the term Trinity will do. Perhaps on the other side of the grave we will learn of other dimensions, but for now, 3 is enough.